1. Field of Invention
This invention relates generally to ophthalmologic surgery and, more particularly, to retinal detachment surgery.
2. Background Art
Retinal detachment surgery involves a method of closing breaks, bringing the two layers of the retina back together, and getting rid of fluid under the retina. The retina is a thin nerve membrane that detects light entering the eye. Nerve cells in the retina send signals of what the eye sees along the optic nerve to the brain. The retina lines the back two-thirds of the eye and is made up of two layers: the sensory retina and the retinal pigment epithelium (RPE). The macula, near the center of the retina at the back of the eyeball, provides the sharp, detailed, central vision a person uses for focusing on what is directly in the line of sight. The rest of the retina provides side (peripheral) vision, which lets a person see shapes but not fine details.
Retinal detachment can occur when the two layers of the retina, the sensory retina and the retinal pigment epithelium (RPE), become separated from each other and from the wall of the eye. Retinal detachment can lead to severe vision loss or blindness. Although retinal detachment can occur at any age, it is most common in older adults. If a retinal detachment has occurred, a new defect, shadow, or dark curtain across part of the visual field that does not go away may be noticed. Because detachments usually affect side vision first, a defect may not be noticed until the detachment has gotten bigger. Retinal detachment may require immediate surgery to prevent permanent vision loss. Retinal detachment surgery is a method of closing breaks, bringing the two layers of the retina back together, and getting rid of fluid under the retina. The goals of surgery are to reattach the retina, prevent infection during the healing process and to prevent or reverse vision loss. Many retinal detachments can be repaired with sclera buckle surgery or pneumatic retinopexy.
The retina detaches by separating from the back wall of the eye. When it is removed from its blood supply (the choroid), it will lose nourishment and result in a loss of some vision if not repaired in time. This retinal tear may be caused by trauma or by a vitreous detachment (or “posterior vitreous detachment”). Vitreous detachment, not uncommon in older people, results from the vitreous fluid shrinking and pulling away from the retina. This causes “floaters,” which do not damage the retina or vision. However, for a certain percentage of individuals, the vitreous continues to pull away near the torn area and could peel the retina from its normal position in the eye. The sudden onset of light flashes and floaters could be the warning signs of an impending retinal detachment.
There are various common methods of repairing a retinal detachment, which include, sclera budding surgery. During this procedure the ophthalmologist places a piece of silicone sponge, rubber, or semi-hard plastic on the outer layer of your eye and sews it in place. This relieves traction on the retina, preventing tears from getting worse, and it holds the layers of the retina together. Other methods for treating retinal tears include Pneumatic retinopexy, Vitrectomy, Laser photocoagulation, in which a laser beam is use to seal the tear in the retina by way of photocoagulation, or Cryopexy (freezing), in which your eye doctor uses a probe to freeze and seal the retina around the tear. However, sclera buckling surgery is likely the most common. The decision about when to treat a retinal tear is based on whether the tear is likely to progress to a retinal detachment. If the tear is not likely to lead to a detachment, treatment may not be necessary.
A sclera buckle is produced by a piece of silicone sponge, rubber, or semi-hard plastic that can be placed by the surgeon on the outer layer of the eye (the sclera, or the white of the eye). The material is sewn to the eye to keep it in place. The buckling element can be left in place permanently. The element pushes in, or “buckles,” the sclera toward the middle of the eye. This buckling effect on the sclera relieves the pull (traction) on the retina, allowing the retinal tear to settle against the wall of the eye. The buckle effect may cover only the area behind the detachment, or it may encircle the eyeball like a ring. By itself, the buckle does not prevent a retinal break from opening again. Usually extreme cold (cryopexy) or less commonly, heat (diathermy) or light (laser photocoagulation) is used to scar the retina and hold it in place until a seal forms between the retina and the layer beneath it. The seal holds the layers of the eye together and keeps fluid from getting between them. By itself, the buckle may not prevent a retinal break from opening again. Usually extreme cold (cryopexy) or less commonly, heat (diathermy) or light (laser photocoagulation) is used to scar the retina and hold it in place until a seal forms between the retina and the layer beneath it. The seal holds the layers of the eye together and keeps fluid from getting between them. Sometimes the surgeon may inject a gas bubble into the patient's eye to close the break and prevent more fluid from passing through it during surgery. The surgeon may drain the fluid under the detached retina through a tiny hole in the sclera. If there is only a small amount of fluid, draining it may not be needed.
Sclera buckling may pose some risks or complications. The eye may become infected. The suture may promote infection and increase the healing time and may be a source of irritation. The plastic or rubber of the buckling device may rub on other parts of the eye, become worn and/or move out of place, or become a site of infection. A better method is needed that addresses the potential problems caused by exterior sutures, the irritation and potential infection and addresses the risk of suturing a sponge or budding in place.